Looking above at the routings we know now our initial routing from Newark Airport to our entry point COLOR. We also know already our NAR (North American Route): N43A, which goes from KANNI to COLOR.
Finally we append the requested mach speed and flight level for the crossing. This must be filed as well if the flight level and/or mach speed doesn't change.

So now we have our complete route on the Canadian side: MERIT DCT HFD DCT PUT DCT BOS DCT KANNI N43A COLOR/M081F380

Domestic Departure

We now have to plan the route from the end of NAT W to Heathrow Airport (EGLL). So all we need to find now is our arrival route into Heathrow.

2 STARs are available for western arrivals:

The Ockham 2 Fox-Trot (OCK2F) STAR, which starts at BEDEK, near CPT on the Y3 airway, and

The Bovingdon 1 Bravo (BNN1B) STAR which starts at NUGRA, near Birmingham then descends south to BNN via Wescott NDB (WCO).

We will enter the European Airspace west of the coast of Ireland so the choice is clear: We will use the OCK2F arrival via BEDEK, so all we have to do is plan the route via the available airways: UN523 CRK UL607 NUMPO Y3 BEDEK OCK2F